Monolithic Power Systems Inc. MCS1806GS-5-50-P

Overview

MCS1806GS-5-50-P from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±50A bidirectional DC/AC sensing with 5V single-supply operation, ±2.5% total output error over -40°C to +125°C, 40 mV/A sensitivity, and 3kVRMS isolation rating. It replaces optocouplers in high-side motor phase current monitoring and switch-mode power supply over-current protection circuits where compact SOIC-8 footprint and magnetic field immunity are critical.

For engineers reviewing the MCS1806GS-5-50-P datasheet, MCS1806GS-5-50-P pinout, MCS1806GS-5-50-P application, or MCS1806GS-5-50-P equivalent, key selection criteria include its 500VRMS working voltage, 0.9mΩ internal conductor resistance, adjustable 100kHz bandwidth via external FILT capacitor, ratiometric analog output, and factory-trimmed offset stability across temperature.

Technical Context

The MCS1806GS-5-50-P implements differential Hall sensing with two integrated transducers (PMCF1 = 0.6 mT/A, PMCF2 = 0.3 mT/A) to cancel stray magnetic fields, combined with spinning current offset cancellation yielding ±10 mV zero-current offset over full temperature range. Its primary conductor is internally connected across pins 1–2 (IP+) and 3–4 (IP−), enabling direct in-line current measurement without shunt resistors.

Galvanic isolation is achieved via reinforced insulation between primary current path and signal side, certified to IEC62368-1 with 3000VRMS withstand voltage and 500VRMS working voltage. The device uses an internal 1.5kΩ filter resistor and 1nF capacitor to enable bandwidth adjustment up to 100kHz using an external capacitor on the FILT pin.

Key Specifications

Pinout & Package

Package: SOIC-8 (5mm × 4mm, 1.57mm height), RoHS-compliant, MSL Level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated current sensing applications.

Compared with ACS724LLCTR-50AB-T and TMC1100-50A, the MCS1806GS-5-50-P uniquely delivers 3kVRMS isolation, 5V operation, and user-adjustable bandwidth in a standard SOIC-8-making it optimal for space-constrained, high-reliability industrial and automotive power conversion where safety certification and design flexibility are mandatory.

Availability

MCS1806GS-5-50-P is available at Aetrix Electronics and suitable for motor controls, switch-mode power supplies, and automotive onboard chargers requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp-up.

Supply support for MCS1806GS-5-50-P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs, with over 20 years of expertise in DC/DC converters, LED drivers, and isolated sensing solutions.

The MCS1806 product line delivers integrated Hall-effect current sensors with reinforced galvanic isolation for industrial motor drives, renewable energy inverters, and electric vehicle charging systems-designed to replace optocouplers and discrete shunt-based architectures.

FAQ

What is the maximum continuous primary current the MCS1806GS-5-50-P can handle without exceeding junction temperature limits?

The device supports ±50A continuous primary current at ambient temperatures up to +85°C on a 2oz copper PCB with 250mm² thermal pad, assuming 0.9mΩ conductor resistance yields ≤2.25W dissipation. At higher ambient temperatures or reduced copper area, derating is required per Figure 10 in the datasheet; maximum junction temperature remains 165°C.

How does the FILT pin affect bandwidth, and what capacitor value achieves 20kHz cutoff?

The FILT pin forms an RC filter with internal RFI = 1.5kΩ and CFI = 1nF. Using fBW = 1/(2π × RFI × (CF + CFI)), a 5.3nF external capacitor yields ~20kHz 3dB bandwidth. Capacitor tolerance directly impacts accuracy; X7R dielectric with ±10% tolerance is recommended for production designs.

Can the MCS1806GS-5-50-P measure AC currents with high harmonic content, such as those in PFC circuits?

Yes-the device maintains linearity up to 100kHz bandwidth and exhibits no magnetic hysteresis, enabling accurate reconstruction of distorted waveforms with up to 5th harmonic content (e.g., 1kHz fundamental + 5kHz harmonics). Total output error remains within ±2.5% across the full ±50A range at 25°C.

What is the impact of supply voltage variation on output accuracy, and how is ratiometry verified?

Ratiometric performance is quantified by KSENS (98–102%) and KVO (99–101%) coefficients, measured across VCC = 4.5V to 5.5V. This ensures VOUT scaling matches supply changes-e.g., a 5% VCC drop causes ≤2% deviation in full-scale output, preserving closed-loop control stability without recalibration.

Does the MCS1806GS-5-50-P require external calibration for zero-current offset in production systems?

No-factory trimming achieves ±10mV zero-current offset over -40°C to +125°C, translating to ±0.25A equivalent current error at 40mV/A sensitivity. This eliminates production calibration steps; system-level offset correction is optional only for sub-0.1% absolute accuracy requirements.

How is isolation integrity validated during manufacturing, and what standards apply?

Every unit undergoes 100% production testing per IEC62368-1 for 3000VRMS withstand voltage at 60 seconds. Dielectric surge strength is certified to 6000V per IEC61000-4-5 (5 pulses), and external clearance/creepage distances are fixed at 4.2mm-meeting reinforced insulation requirements for basic and supplementary protection in end equipment.

What PCB layout practices maximize thermal performance and magnetic immunity?

Route IP+ and IP− traces symmetrically with minimum loop area; place VCC bypass capacitor within 2mm of pin 8; isolate GND (pin 5) from power ground using split planes; and avoid routing noisy signals (e.g., gate drivers) parallel to FILT or VOUT traces. Thermal pads under the SOIC-8 body improve heat dissipation by ≥15°C.